From today, some people in England will be able to form a "support bubble" but what does that mean and how will it work?
Who can have a support bubble?
Adults living alone or single parents living with children under the age of 18
What can they do?
They can form a bubble with one other household which means they will effectively be treated as a single household for the purpose of the lockdown rules.
They can visit each other's homes and stay overnight if they want. They will not have to observe the two-metre social distancing rule.
Can people switch between bubbles?
Does it matter where the two households are?
No, but officials have suggested people should stay local if possible.
Can people who are shielding be part of a support bubble?
No. At the moment officials say it is too soon for them to join support bubbles.
Who could benefit?
The prime minister has said that the bubbles are aimed at helping people who live alone and have struggled with a lack of human interaction since lockdown began.
Elderly people living alone could form a bubble with the household of an adult son or daughter, while single parents could link with their own parents to share childcare.
Couples who do not live together will also be able to visit and stay with each other.
If one half of a couple shares a flat or house with one or more other people, they can see their partner if they live alone. If both partners share a home with other people, they cannot see each other.
And if several people share a flat or house and all have partners who live alone, only one will be able to see their partner.
If two grandparents live together in one household, they can only visit their children and grandchildren if their son or daughter is the only adult in his or her household.
If a grandparent lives alone and has two or more children who each live alone, they must choose between them.
What about parents who are separated but share childcare with the children moving between the two households?
The childcare arrangements can continue. If the parents are the only adult in their respective households they can form a bubble with another household. The children could potentially be in two bubbles, one for each parent.
Do the bubbles have to be registered?
No, it will be based on trust.
What if someone in a bubble develops coronavirus symptoms?
All members of the bubble must isolate themselves for 14 days.
Are there any concerns?
In a 13 May meeting, the Scientific Advisory Group for Emergencies (SAGE) urged "strong caution" and warned social bubbles could create "significant unwanted effects", particularly if introduced as other rules are eased.
But the group's main concern was having larger households in a bubble together, something that would bring "significant risk", they said. The government has not yet proposed this.
Is it only in England?
A similar scheme in Northern Ireland starts on Saturday. This allows a person who lives alone to visit someone else's home, including staying overnight.
They do not qualify if they have a child or children living with them.